In chapter 2, I will go into detail on how the code may be managed and deciphered. Three tools will be introduced that was used for the analysis, easy browsing and management of code. The first is a tool called LXR which allows source code to be browsed as a web page with identifiers and functions highlighted as hyperlinks to allow easy browsing. The second is a tool called gengraph which was developed for this project and is used to generate call graphs starting from a particular function with the ability to limit the depth and what functions are displayed. All the call graphs shown in these two documents were generated with it. The last is a simple tool for managing kernels and the application of patches. Applying patches manually can be time consuming and the use of version control software such as CVS1.2or BitKeeper1.3 is not always an option. With this tool, a simple spec file can be provided specifying what source to use, what patches to apply and what kernel configuration to use.
In the subsequent chapters, each part of the implementation of the Linux
VM will be discussed in detail such as how memory is described in an
architecture independent manner, how processes manage their memory, how
the specific allocators work and so on. Each will refer to the papers that
describe closest the behavior of Linux as well as covering in depth the
implementation, the functions used and their call graphs so the reader will
have a clear view of how the code is structured. For a detailed examination
of the code, the reader is encouraged to consult the companion document.